A seven-year effort to put better teachers in Hillsborough County schools is costing the system millions of dollars more than officials projected. And the district’s partner in the project, the Bill & Melinda Gates Foundation, is spending $20 million less than expected. The numbers, found in recent reports, differ significantly from what was commonly understood about the high-profile partnership, known as Empowering Effective Teachers. The district was to raise $102 million for its part, much of it by aggressively pursuing grants from local corporations and other entities. Gates was to kick in $100 million, for a total of $202 million. But as the project stands in its final year, the district’s contribution will total $124 million in money and labor, while the Gates organization is paying only $80 million, the reports state. What’s more, the district has put the…